Machine for grinding concave spherical surfaces



A. DANIELSSON.

MACHINE FOR GRINDING CONCAVE SPHERICAL SURFACES.v APPLICATION man OCT. 1. 1919..

1;:3523790. PatentedSept. 14, 1920.

2 SHEETS-SHEET I- )Z A Z Inventor A .DmteI/ssozp,

Amrzwy 'A. DANIELSSON. MACHINE FOR GRINDING CONCAVE SPHERICAL SURFACES. APPLICATION FILED OCT-7.1919.

1,352,790, PatentedSept. 14,1920.

2 SHEETS-SHEET 2- V UNITED STATES PATENT OFFICE.

AXEL DANIELSSON, OF GOTTENBORG, SWEDEN.

MACHINE FOB. GRINDING CONCAVE SPHERICAL SURFACES.

To all whom it may concern:

Be it known that I, AxEL DANIELssoN, a subject of the Kin of Sweden, residing at Gottenborg. Kingr om of Sweden, have in vented certain new and useful Improvements in Machines for Grinding Concaved Spherical Surfaces, of which the following is a specification.

The present invention relates to a proceeding for grinding concave spherical surfaces as well as to a device for carrying out this proceeding.

The object of the invention is a proceeding by means of which cavities are made. exactly spherical. The invention has also for its object to provide simple means for carrying out the proceeding.

To this and other ends the invention consists in certain improvements, which hereinafter will be fully described and ascertained in the annexed drawing.

In the accompanying drawing there is shown in Figure 1 a plan view of a grinding machine for carrying out the proceeding; in Fig. 2 a side elevation of the same machine and in Fig. 3 a. section on the line AA in Fig. 2.

Referring now to the drawing' 19 indicates a sleeve-shaped work-piece, fixed to a shaft 9 by means of a holder 21 on a face plate 20, which shaft also is provided with a wheel 7 operating a toothed bar 27 on the under sideof the-table can be slid in a guide 8. Thegear-wheel4 on the shaft 9 meshes with the shaft 2 by means of a gearwheel 41 on said last mentioned shaft. The shaft 2 is journaled in two bearings 61 and provided with. a belt-pulley 3 driven by a belt 32.. The frame 1 is provided with a bracket 22, carrying a table 24., which is by means of a screwed spindle 26 provided with a hand-wheel 25 slidable in a guide 23 and positioned at an oblique angle to the guide 8. A shaft 16, provided with a belt-pulley 18 is journaled in bearings 15 on the table 24, said shaft being driven by means of a Specification of Letters Patent. Patented Sept, 14 1920, Application filed October 7, 1919. Serial No. 329,178. I

,belt 81 on the pulley 18. The center-line of the shaft 16 intersects the extended centerline of the shaft 9 in the center of the spherical surface to be ground. The shaft 16 carries the grinding-Wheel 28 within range of the work-piece'l9.

In order to make it'possible for the grindlng wheel to be introduced into the sleeveshaped work-piece 19, the diameter of the grinding wheel as clearly shown in the fi ure must be made not larger than the d1- ameter of the a ertures of the work-piece, the boundary of w ich'apertures are preformed bythe spherical surface of which the cavity of the work-piece forms a portion. The planes of these apertures form tangential planes to the smaller circle, shown in the tersect each other in the center of the spheri'-' cal surface of the cavity of the work-piece, an exactly spherical surface is imparted within the workiece 19. The grinding is mainly effected albng the surface of a zone of a sphere, forming the intersection between the operative surface of the grindingwheel and the spherical surface within the work-piece. In the same degree as the grinding-wheel is worn, it is fed backward axially on its shaft of rotation by means of the hand-wheel 25, so that the grinding-wheel from the position a, successively takes in the positions a and a and finally a as shown with dot and dash lines in the drawing. During the whole time an exactly spherical surface will be performed, since theabove-mentioned mutual positions of the shafts, tool and work-piece continually are I present. When the limit and cannot be used further for the same size of work-piece, but must be re-' placed by another grinding-wheel. Thus it grinding-wheel has been diminished to the sue a,, it has reached its is necessary that the grinding wheel during ascertained the nature of my said invention, and in What manner the same is to be performed, I declare that What I claim is A machine for grinding concave spherical surfaces comprising in combination arotatable shaft, a grinding-tool on one end thereof, another rotatable shaft, a holder on the last mentioned shaft for supporting a ring-shaped Work-piece so as toleave a free space between the Work-piece and the oppos: ing end surface of the holder, and means for journaling said shafts so that their center lines intersect each other in ithe center of the spherical surface to be ground, substantially as and for the purpose set forth.

In testimony whereof I have afiixed my signature. AXEL DANIELSSON. 

